DSpace Собрание:http://hdl.handle.net/11701/5830
Sat, 25 May 2019 15:51:19 GMT2019-05-25T15:51:19ZChromatographic quantitation by absolute calibration using an additional standardhttp://hdl.handle.net/11701/5873
Название: Chromatographic quantitation by absolute calibration using an additional standard
Авторы: Prokofiev, Denis V.; Zenkevich, Igor G.
Краткий осмотр (реферат): Precision of quantitative chromatographic analysis using absolute calibration is determined by the
reproducibility of absolute areas (heights) of analyte peaks. Their dispersion, mainly associated
with losses on samples during injection, lead to an insufficient accuracy of quantitation. Solving
this problem implies using an additional standard for absolute calibration. The proposed version
is based on introducing of an additional standard to calibration and target samples and on the
replacement of absolute peak areas with relative values, namely S(analyte) / S(additional standard).
It is noteworthy there are no restrictions on the chemical origin of the additional standard.
In this case, the mode proposed allows increasing precision (reduce random errors) of results, as
well as reducing the number of replicates to achieve a required accuracy. Furthermore, there is
no significant complication of the analytical procedure as a whole. Refs 10. Figs 3. Tables 3.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58732016-09-01T00:00:00ZComplexation in system Zn(HCO2)2—NH(CONH2)2—H2O at 25℃ and study of physical and chemical properties of the new solid phasehttp://hdl.handle.net/11701/5872
Название: Complexation in system Zn(HCO2)2—NH(CONH2)2—H2O at 25℃ and study of physical and chemical properties of the new solid phase
Авторы: Shaikieva, Nurzat T.; Kadyrkulova, Saltanat O.; Akhmatova, Zhyldyz T.
Краткий осмотр (реферат): The solubility and the nature of the solid phase in the system Zn(HCO2)2—NH(CONH2)2—H2O
at 25℃ were investigated by isothermal method. The concentration range of crystallization of
the new incongruently soluble compound Zn(HCO2)2 · NH(CONH2)2 · H2O with molar ratio of
1 : 1 : 1 was set in system. The individuality of the new compound Zn(HCO2)2 · NH(CONH2)2 ·
· H2O was confirmed by chemical, X-ray, differential thermal analysis and IR spectroscopic analysis.
It has been shown that, in a complex compound, the coordination of a ligand takes place
through an oxygen atom in a carbonyl group. It is shown that the thermolysis of the complex
compound is a complex multistage process, which includes stages of complex dehydration and
decomposition. The final product of decomposition is zinc oxide. According to X-ray analysis a,
b, c, d and hkl unit cell parameters, the value-spacings and intensities of the diffraction patterns
of peaks were calculated. The resulting new compound Zn(HCO2)2 · NH(CONH2)2 · H2O has
orthorhombic syngony. The composition of the new complex compound set by chemical analysis,
matches the theoretically calculated composition and has a constant composition. Refs 4. Figs 3.
Tables 2.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58722016-09-01T00:00:00ZReaction between gelled HCl and calcite or dolomite at high mineralizationhttp://hdl.handle.net/11701/5871
Название: Reaction between gelled HCl and calcite or dolomite at high mineralization
Авторы: Andreev, Oleg V.; Antonov, Sergey M.; Kiselev, Konstantin V.
Краткий осмотр (реферат): The paper is devoted to reactions of the interaction of gelled aqueous salt solutions (CNaCl =
=15 wt %) of HCl (12 wt %) with CaCO3, Ca1.16Mg0.84(CO3)2 carbonate core minerals on the
quasi-static conditions at a temperature of 10, 17, 25℃. Increase of HCl viscosity by xanthan
gum, scleroglucan biopolymers and amidoalkylbetaine, reactions of acid-carbonate interaction
take place in the diffusion region. The values of apparent activation energy Ea reactions between
HCl with dolomite and calcite are determined by the structural and mechanical properties of
the liquid phase. Viscosity of HCl is stable for more than 4 hours at t = 12℃, P = 10 MPa,
CNaCl = 15 wt %. Viscosity of micellar solution HCl (12 wt %) + Amidoalkylbetaine (6,5 wt %)
is equal to 109 mPa·s, at neutralization increases to more than 600 mPa·s. Initial micellar solution
has 60 wt % of the micelles with a size in the range from 1 to 10 nm, 40 wt % of micelles
have sizes 200–1000 nm. The sizes of micelles are increased to 2000–7000 nm, structural and
mechanical properties of the solution are change. Homogeneous profile of dissolution of carbonate
CaCO3, Ca1.16Mg0.84(CO3)2 after interaction with gelled HCl was imaged by electron
microscope. Refs 20. Figs 5. Tables 2.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58712016-09-01T00:00:00ZChromatographic and mass spectrometric characteristics of monoesters of phthalic acidhttp://hdl.handle.net/11701/5870
Название: Chromatographic and mass spectrometric characteristics of monoesters of phthalic acid
Авторы: Fakhretdinova, Lilia N.; Zenkevich, Igor G.
Краткий осмотр (реферат): In contrary to the widespread and thoroughly characterized disubstituted esters of benzene-1,2-
dicarboxylic (phthalic) acid, their primary metabolites — monosubstituted esters of phthalic
acid — have not yet to be characterized with standard mass spectra, as well as gas chromatographic
retention indices on standard non-polar stationary phases. We argue that is the cause of
a significant number of errors in their GC-MS identification. To prevent such errors these esters
should be characterized with standard mass spectra, as well as gas chromatographic retention
indices on standard non-polar stationary phases. The results of the determination of these analytical
parameters for series of monoesters of phthalic acid are discussed. As it is shown, one of
the useful modes of GC data interpretation is based on the retention indices correlation for monoesters
and diesters as most related structural analogues. The monoesters under consideration
are characterized additionally with retention indices in reversed phase high performance liquid
chromatography. Refs 28. Figs 2. Tables 4.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58702016-09-01T00:00:00ZPhase formation and stability of solid solutions in nanosized zirconia based powders, obtained by cryochemical routehttp://hdl.handle.net/11701/5869
Название: Phase formation and stability of solid solutions in nanosized zirconia based powders, obtained by cryochemical route
Авторы: Kurapova, Olga Yu.; Konakov, Vladimir G.; Golubev, Sergey N.; Ushakov, Victor M.
Краткий осмотр (реферат): The paper reports the correlations in the sequence “amorphous phase → metastable crystalline
solid solution → stable crystalline solid solution” in nanosized ZrO2, 5CaO—95ZrO2 and 9CaO—
91ZrO2 precursors, obtained by reversed co-precipitation technique with following fast freezing
in liquid nitrogen, freeze-drying and pan drying. It has been found that kinetic stabilization
of metastable zirconia phases in the required region of temperatures and concentrations can be
achieved via correct post-treatment of gels obtained by reversed co-precipitation technique. The
use of cryochemical treatment allows to eliminate powders agglomeration up to 1000℃. Refs 22.
Figs 6. Tables 4.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58692016-09-01T00:00:00ZMethod of protein stabilization based on prediction of intrinsically disordered regions. Stabilization of protein Gαohttp://hdl.handle.net/11701/5868
Название: Method of protein stabilization based on prediction of intrinsically disordered regions. Stabilization of protein Gαo
Авторы: Nagibina, Galina S.; Dzhus, Uliana F.; Glukhov, Anatoly S.; Melnik, Tatiana N.; Melnik, Bogdan S.
Краткий осмотр (реферат): Protein Gαo from Drosophila melanogaster has been studied. We have designed an SS-bridge
in this protein in such a way that its stability could be increased. The choice of a region in the
polypeptide chain for insertion of the cysteine bridge was based on calculations performed using
programs for the prediction of intrinsically disordered proteins. In our previous paper we proposed
that, in structured proteins, these programs predict “weakened” protein regions unable to have
a rigid structure without additional hydrophobic interactions rather than intrinsically disordered
regions. Consequently, insertion of SS-bridges in such regions will most probably lead to stabilization
of the protein. It was just this approach that was used in the presented study. It is demonstrated
with the microcalorimetry method that the insertion of the designed SS-bridge resulted in
4 K increase in the melting temperature of one domain of protein Gαo. Refs 20. Figs 3. Tables 1.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58682016-09-01T00:00:00ZLuminescent and UR-spectral studies of doped polycrystalline triptycenehttp://hdl.handle.net/11701/5867
Название: Luminescent and UR-spectral studies of doped polycrystalline triptycene
Авторы: Nosova, Darja A.; Kushaeva, Mata A.; Zarochentseva, Elena P.; Vysotskaya, Sofja O.; Klemesheva, Nina A.; Tsyganenko, Aleksej A.
Краткий осмотр (реферат): The luminescent and excitation spectra of polycrystalline triptycene doped by diphenyl and triazole
have been studied. In triptycene—diphenyl systems sensitized luminescence was observed
when the excitation of the matrix (triptycene) led to luminiscence of the energy acceptor — the
dopant. For the latter system the maximum luminescence of the donor and that of the excitation
band of the energy acceptor differ by 10 nm, unlike the triptycene—triazole system where
differences amount to 75 nm and the sensitized luminescence was not detected. This result is
consistent with the notion that effective electronic excitation energy transfer occurs in systems
with the greatest overlap of the emission spectrum of energy donor with the excitation spectrum
of the acceptor. The IR study of triptycene films deposited at 77 K reveals irreversible structural
changes upon raising the temperature indicating a possible effect of recrystallization on the
luminescence spectra. Refs 12. Figs 7. Tables 1.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58672016-09-01T00:00:00ZConformational and kinetic properties of hyperbranched architecture poly(methyl methacrylates) in solutionshttp://hdl.handle.net/11701/5866
Название: Conformational and kinetic properties of hyperbranched architecture poly(methyl methacrylates) in solutions
Авторы: Yevlampieva, Natalia P.; Kurmaz, Svetlana V.; Iljasova, Yulia V.
Краткий осмотр (реферат): Molecular properties of hyperbranched macromolecules-nanoparticles obtained by copolymerization
of methyl methacrylate with the branching agents m-ethyleneglycol dimethacrylates at m = 1
and m = 3, have been studied by the methods of hydrodynamics and dielectric spectroscopy. By
means of comparison with the linear poly(methyl methacrylates) it is shown that the conformational
properties of these macromolecules can be characterized as the intermediate between
statistical Gaussian coils of linear polymers and dendrimers. Their hydrodynamic behavior in
solution does not correspond to solid unpenetrative nanoparticles. The influence of the length of
branching agent on kinetic properties of hyperbranched copolymers of methyl methacrylate with
m-ethyleneglycol dimethacrylates has been established. Refs 28. Figs 8. Tables 1.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58662016-09-01T00:00:00ZFerromagnetic resonance as a diagnostic method of the quality and functional properties of multilayer structureshttp://hdl.handle.net/11701/5865
Название: Ferromagnetic resonance as a diagnostic method of the quality and functional properties of multilayer structures
Авторы: Kupriyanova, Galina S.; Orlova, Anna N.; Zubin, Andrei Yu.; Astashenok, Artem V.
Краткий осмотр (реферат): The article presents the main results of an investigation into the structural and magnetic parameters
of samples formed on single-crystal (MgO) and the amorphous substrates Si/SiO2 structures.
In order to identify individual contributions and anisotropy constants, a series of experiments was
carried out to investigate the angular dependence of the resonance field and linewidth of the FMR
depending on the direction of the external magnetic field in the two geometries. Quality indicators
such as the paramagnetic phase, the presence of impurities, and an analysis of the functional
properties were assessed. The radiophysical methods features for the diagnosis of prospective
structures were shown. Refs 17. Figs 3. Tables 2.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58652016-09-01T00:00:00ZNMR relaxation of water in building materials during thermal cyclinghttp://hdl.handle.net/11701/5864
Название: NMR relaxation of water in building materials during thermal cycling
Авторы: Adelson, Veronica Ya.; Chernyshev, Yuri S.; Frolov, Vyacheslav V.
Краткий осмотр (реферат): This article presents the results of the study of changes in the properties of porous ceramics
and concrete under the influence of “freeze—thaw cycles” produced by employment of nuclear
magnetic relaxation. The measurements of nuclear magnetic relaxation times T1 and T2 were
performed on saturated water samples with 60 cycles of freezing using spin echo methods “CPMG”
(T2) and “inversion — recovery of the equilibrium of nuclear magnetization” (T1). The results
are interpreted assuming the two-exponential dependence of the magnetization on the time in
the process of establishing equilibrium. A relation between periodic temperature effects and the
change in the number of pores and their connectivity was found. To confirm the assumption of the absence of the effect of the paramagnetic ions on the relaxation process, an experiment with
samples saturated with heavy water was carried out. Refs 9. Figs 8. Tables 2.Thu, 01 Sep 2016 00:00:00 GMThttp://hdl.handle.net/11701/58642016-09-01T00:00:00Z